Members of the original Haskell committee, authors of books / popular libraries / etc, contributors to GHC, and so on and so forth.
The person who is most of all associated with Haskell (i.e. would've been the benevolent dictator of Haskell if Haskell wasn't designed by a committee).
Lead developer of GHC, one of the members of the original Haskell committee, and the author of innumerable papers about Haskell, type theory, and implementation details of GHC. Still active and working on GHC.
Has seemingly a thousand interests (a whole channel – #haskell-lens – exists around the discussion of things that Edward is interested in). Going through Hackage:
- lens (it's hard to explain what lens is, see for yourself)
- a dozen category-theory-related libraries: profunctors, kan-extensions, etc
- math and math-related libraries: ad, linear, compensated, log-domain
- algorithms and data structures: hyperloglog, discrimination, structures
- trifecta (a parsing library)
- gl (bindings to OpenGL)
Also wrote a Haskell-like language called Ermine, chairs the Haskell Core Libraries Committee, organised the Boston Haskell group, has been the administrator of haskell.org for Google Summer of Code, writes about Haskell, gives lots of talks, and posts long comments on Reddit (like this fun-to-read list of things that are wrong with Scala).
Michael has created a great number of open source libraries including the Yesod web framework and de-facto standard streaming library
conduit. He is director of engineering at FP Complete. It's difficult to overestimate his contribution the Haskell ecosystem (at least to useful and pragmatic part of it).